At present, micro optical image stabilization voice coil motors have been widely applied to high-end mobile phones, and can effectively reduce the probability of blurred images during photographing in a low-light environment, and reduce the disturbing jitter in the image. However, compared with ordinary autofocus motors, optical image stabilization voice coil motors have a complex design and low production yield and efficiency. Therefore, image stabilization voice coil motors are mainly applied to high-end mobile phones and have not been widely applied to middle- and low-end mobile phones, which has severely affected use experiences of mobile terminal users such as mobile phone users.
Micro optical image stabilization voice coil motors may be classified into the following three types: camera-module-axis-shifting-type in which the voice coil motor controls the lens and the image sensor to rotate together; lens-translation-type in which the voice coil motor controls the lens to translate, with the image sensor being kept still; lens-axis-shifting-type in which the voice coil motor controls the lens to rotate, with the image sensor being kept still.
Each of the three types of voice coil motors has its own advantages and drawbacks. For example, the camera-module-axis-shifting-type voice coil motor has advantages of optimum optical image stabilization effect and image quality, but has drawbacks of a heavy weight and thus a large power consumption. The lens-axis-shifting-type voice coil motor has advantages of a relatively simple structure and easy production, but has a drawback of a possibly reduced resolution at image edges during optical image stabilization. The lens-translation-type voice coil motor has a structure complexity and an image edge resolution in between those of the camera-module-axis-shifting-type voice coil motor and the lens-axis-shifting-type voice coil motor that are acceptable for manufacturers and users, and an acceptable power consumption as well. Therefore, the lens-translation-type voice coil motor has become a prevalent component used in image stabilization solutions for mobile terminals, such as mobile phones.
However, conventional lens-translation-type voice coil motors generally include a large number of components and thus have a complex structure, which is not beneficial for production, and makes it difficult to achieve improved reliability and reduced costs. Moreover, loadstones in these lens-translation-type voice coil motors are generally located in a movable structure, making them susceptible to interferences from external magnetic fields and have a degraded performance.